1. Field of the Invention
The present invention relates to a method and an apparatus for the preparation of solutions to be manufactured from at least two concentrates and a solvent as well as to a connector and to a concentrate container unit containing a concentrate.
2. Description of the Related Art
An important application possibility for such a method or for such an apparatus is dialysis in which high purity haemodialysis solutions are required which have to be made available in compositions and concentrations matched to the patients. The haemodialysis solutions are usually manufactured from two concentrates which a re stored in separate containers and only mixed in the course of the manufacture of the haemodialysis solution.
In the manufacture of haemodialysis solutions it must absolutely be ensured that no errors are made since incorrect compositions of the haemodialysis solution or incorrect concentrations of the components contained therein can result in a substantial risk for the patent to be treated as part of the dialysis.
Batch systems are known in which the medical staff making the haemodialysis solution available fill the different concentrates required for the manufacture into a flushing vessel. These are subsequently separated from pre-heated high purity water or are mixed with this and flushed into a receiving vessel which is subsequently taken to the site of the treatment to be carried out. While the control of the finished haemodialysis solution can take place by a conductivity measurement, errors in the preparation of the haemodialysis solution can in particular not be precluded if the incorrect solution and the desired solution have similar conductivity values.
It is therefore the object of the present invention to further develop a method and an apparatus for the preparation of solutions to be manufactured from at least two concentrates and a solvent such that it is simplified and the occurrence of errors in the preparation of the solution is further reduced.
This object is solved by a method for the preparation of solutions to be manufactured from at least two concentrates and a solvent in which, after the placing of concentrate holders into associated recipients, the connection takes place of a first concentrate holder to a solvent source, solvent flows through the first concentrate holder and the solution is led into a collection holder. After the flushing of the concentrate from the first concentrate holder, an automatic connecting of a second concentrate holder takes place, whereupon solvent flows through the second concentrate holder and the solution is likewise supplied to the collection holder.
The object is further solved by an apparatus for the preparation of solutions to be manufactured from at least two concentrates and a solvent having at least two concentrate holders. The apparatus includes feed lines through which the solvent can be led to the concentrate holders, discharge lines by means of which the solutions can be led from the concentrate holders into a collection holder, a connector which connects a solvent source to the first concentrate holder in a first position and the solvent source to the second concentrate holder in a second position, and means by which the connector is movable from the first into the second position.
The object is also solved by a concentrate container unit having a solid or a liquid concentrate received in a concentrate holder and having two first connector elements or two second connector elements. The first connector elements have a membrane closing them and a piercing pin which is in connection with a connection line and which is surrounded by an annular space being in connection with the concentrate holder. The second connector elements are in connection with the concentrate holder and have a membrane closing the second connector elements.
In the method in accordance with the invention, after concentrate holders have been placed into associated receivers, the connection is made of a first concentrate holder to a solvent source; subsequently, solvent flows through the first concentrate holder and the solution is led into a collection holder. After the flushing of the concentrate from the first concentrate holder, an automatic connecting of a second concentrate holder takes place, whereupon solvent flows through the second concentrate holder and the solution is likewise led to the collection holder. In a first preparation phase, the through-flow, and thus the dissolution of the concentrate, takes place exclusively through the first concentrate holder. After the automatic connection of the second concentrate holder, this is flowed through. The substances contained therein are dissolved and likewise flushed out.
The present invention lowers the risk of operator error by automating the addition of concentrate. After the flushing of the concentrate from the first concentrate holder, an automatic switch to the second concentrate holder takes place, whereupon this is flowed through and the solution is likewise led to the collection holder. The operator comfort in such a method is very high due to the simple handling, i.e. the minimization of user steps. User interactions during the preparation time are avoided.
The solvent can be high purity water manufactured by reverse osmosis. A dry concentrate containing NaCl, NaHCO3 and glucose can be present in the first concentrate holder and a liquid concentrate can be present in the second concentrate holder, said liquid concentrate containing as main components the ions K+, Ca2+, Mg2+ and NaCl. Ultra pure haemodialysis solution can be reliably manufactured in this way.
Provision is made in another aspect of the present invention for the automatic connecting of the second concentrate holder to take place when a defined period of time since the start of the flowing through of the first concentrate holder has elapsed, when the conductivity of the solution leaving the first concentrate holder has fallen below a threshold value or when the level in the collection holder has exceeded a pre-determined value. A control unit is accordingly provided in this case which carries out a comparison between the corresponding actual value and a nominal value or limiting value and initiates the automatic connecting of the second concentrate holder when the nominal value or limiting value is reached.
Provision is made in another aspect of the present invention for an automatic flow diversion of the first concentrate holder to take place simultaneously with the automatic connecting of the second concentrate holder.
Confusion is precluded due to the clearly pre-determined order of the concentrate addition. Moreover, the case cannot occur that the one concentrate is added a number of times by accident or that the other concentrate is added a number of times by accident. Nor can the case occur that one of the concentrates is omitted by accident, since the present invention ensures that an automatic connecting and subsequent flowing through of the second concentrate holder takes place after the flushing of the concentrate from the first concentrate holder.
The present invention further relates to an apparatus for the preparation of solutions to be manufactured from at least two concentrates and a solvent. The apparatus has at least two concentrate holders as well as feed lines through which the solvent can be led to the concentrate holders, discharge lines by means of which the solutions can be led from the concentrate holders into a collection holder, a connector which, in a first position, connects a solution source to the first concentrate holder and, in a second position, connects the solution source to the second concentrate holder, and finally means by which the connector is movable from the first position into the second position. After the placing of the concentrate holders into the apparatus in accordance with the invention, or into the receivers of the apparatus provided therefor, the time sequence and the connection and the flow regulation take place automatically. The work of the user is accordingly reduced to putting in the desired concentrate holders.
A connector which can be moved into two positions is known, for example, from EP 0 197 553 A2. The connector disclosed therein is used in transperitoneal dialysis and, depending on the connector position, allows the flow from a dialysis pouch to the patient, into an empty pouch or also the flow from the patient into the empty pouch. The connector has a female connector piece which is connected to a peritoneal catheter via a line. This connector piece can be connected to a male connector piece to allow the inflow of fresh haemodialysis solution from a full pouch into the peritoneal cavity. An empty pouch is connected to the male connector piece via a further line. The female connector piece has a cut-off member which is opened at a pre-set connection status of the connector by a central hose piece of the male connector piece. A fluid connection with both pouches and with the peritoneal cavity is made possible due to the arrangement of a second connection at the male connector piece in interaction with the cut-off member of the female connector piece made as a membrane and with a radial opening in the central hose piece.
It is particularly advantageous for the concentrate holders to be made as disposable articles and to be provided in each case with two self-sealing connector elements. The use of disposable elements provides the advantage that these are of a favourable cost. Due to the self-sealing connections, the concentrate holders are closed before and during the application, whereby operator errors and an incorrect preparation of the solution are prevented and an aseptic state of the haemodialysis solution to be manufactured is ensured. Each of the concentrate holders has two respective connector elements which, depending on the arrangement, allow the inflow into the concentrate holders or the discharge from the concentrate holders.
In another aspect of the present invention, provision is made for the concentrate holders to be made in funnel form. Such a design of the containers allows the optimum and full dissolution of the concentrates and, in addition, in corresponding connection with a discharge line, the complete emptying of the concentrate holders. The advantage thereby results that at best a minimum residual volume remains in the disposable articles after use.
In another aspect of the present invention, provision is made for the connector to have a first connector element being in connection with a first concentrate holder, with a second connector element being connected to a second concentrate holder being able to be inserted into said first connector element, and for a piercing pin to be provided in the first connector element by means of which a membrane closing the second connector element can be cut on the movement of the connector into the second position. Provision is additionally made for the first connector element to have a membrane, preferably a silicone membrane, which terminates it. The membranes are intact before the second concentrate holder is flowed through and only the first concentrate holder is flowed through. In the connection process, the said silicone membrane is first pierced. A sealing connection to the second concentrate holder is thus initially manufactured. Finally, in a further phase of the connection process, the membrane closing the second connector element is pierced by the piercing pin, which results in the flow of the solvent now mainly being led through the second concentrate holder. In this connection, it is favourable, but not necessary, for the flow through the first concentrate holder to be completely suppressed.
In a preferred aspect of the present invention, a connection line is provided which is arranged at the first connector part and through which the solvent can be led from the solvent source to the connector or the solution from the connector to the collection holder.
An annular space can extend around the piercing pin of the first connector element and form a part of the feed line or of the discharge line which connects the connector to the first concentrate holder. Before the connecting, the solvent is guided through the piercing pin and subsequently through the annular space which forms a first part of the feed line which leads to the first concentrate holder. After the connection, the annular space is filled by the second connector element and the solvent is now guided through the piercing pin through the second connector element into the second concentrate holder.
The present invention further relates to a connector having a first connector element which is in connection with or can be connected to a first concentrate holder and having a second connector element which is in connection with or can be connected to a second concentrate holder, with the first connector element being closed by a membrane which can be cut by the second connector element insertable into the first connector element and with the first connector element having a piercing pin by means of which a membrane closing the second connector element can be cut.
The present invention further relates to a concentrate container unit having a solid or liquid concentrate accommodated in a concentrate holder and having two first or two second connector elements, with the first connector elements having a membrane closing them and a piercing pin being in connection with a connection line, said piercing pin being surrounded by an annular space being in connection with the concentrate holder and with the second connector elements being in connection with the concentrate holder and having a membrane closing the second connector elements. The concentrate container unit is advantageously made as a disposable article.
The concentrate container unit can comprise an inflow line and a discharge line which extend from the first and second connector elements to the concentrate holder or from this to the first and second connector elements.
In another aspect of the present invention, provision is made for the membrane closing the first and/or the second connector element to be a silicone membrane.
The concentrate can be a dry concentrate containing NaCl, NaHO3 and glucose or a liquid concentrate which contains as the main components the ions K+, Ca2+, Ng2+ and NaCl. The liquid concentrate can furthermore contain the components and HCl.